A modal dialog box is a dialog box that, at the direction of a user interface program, pops up on a computer user's screen when the user is performing a particular function, and puts the user in a mode where the user is required to work only inside the dialog box. There are many different examples of modal dialog boxes. One example is when a user attempts to exit an electronic document after working on the document, a modal dialog box may pop up on the display asking the user whether the document has been saved to memory. The user is required to interact with this modal dialog box, by either selecting an option in the box that causes the document to be saved, or by selecting a cancel function that allows the document to be exited without being saved. In other examples, modal dialog boxes have an alert message that the user is forced to acknowledge by taking a specified action in the box.
The popping up of a modal dialog box on a user's display may obstruct the user's view of the primary workspace. In some cases, the user can drag the modal dialog box to another area of the screen to see the workspace below the box. In other cases, the modal dialog box cannot be dragged to another area of the screen, and the user must perform the function required by the modal dialog box before the workspace underneath can be seen again.
A modeless dialog box is one that also pops up on a user's screen, but unlike a modal dialog box, does not constrain the user to work only inside the dialog box. Like a modal dialog box, a modeless dialog box may cover up workspace on the display that the user may wish to continue to see. The user may thus be forced to take some type of action to see the workspace below. For example, the user may take an action that removes the modeless dialog box from the display, or that minimizes the box. Many users become irritated by having to take an action in response to a dialog box popping up on a screen and obscuring a portion of the workspace, in order to see the workspace again.